The 25-year-old singer follows in the footsteps of fellow US singing superstar Katy Perry, who won the award last year, reported Daily Mirror.
Swift was presented with her award at the glamorous event by another winner, Sam Smith, who was named Musician of the Year.
Guests at the event at the Sky Garden at London's 20 Fenchurch Street included Pixie Geldof, MIA and Naomi Campbell.
Simon Cowell was recognised for Outstanding Contribution to Entertainment. Burberry boss Christopher Bailey won the Editor's Choice Award, Rosie Huntington-Whiteley was named Model of the Year and 'The Honourable Woman' star Maggie Gyllenhaal won the TV Actress Award.
The event, now in its 18th year, also saw Australian actress Rebel Wilson named Rising Star.
Model and actress Lily Cole, who set up her own social network which invites people to give their services and skills away to help others, won the H&M Conscious Award.